Telephone-transmitter.



N. H. HOLLAND.

TELEPHONE TRANSMlTTER.

APPLICATION FILED MAY I3. 1913.

Patented May 2%, 1917.

UNITED stmrus PATENT mm.

manta. nor-Lam),- or wns'r omen, NEW musty, assrenoa, BY imam: assIenmas, mu m flunsar ia'rmrr conr To concern:

ANY, OF WEST ORANGE, NEWJEBSEY, A.

rnnnrnons-rmsmmn.

Be it I, Nnwmur H. Honmuin,

' a subject m5 theKin'g of Great Britain, and

' lowing a description.

" .1 rmident of "West Orange, in the county of v Em; and State of New ersey, have invent- .ed a new and useful Improvement in Telephone-Th of which the 01 My invention lates to telephone trans- L a and more particl llarly to microphone wherein the desired variations imieurrent are produced by variations in resistance caused by varying the V presslue upon-a quantity of finely divided or granular conductive material, such as carbm, which is included between electrodes in the carrying the current, the requisite changes 1111 presure being efi'ected between f the electrodes and the. granular material by a idiaphra I or other means adapted to be set into 7 ration by the sound'waves from a scurce-of-sound, such as thehuman voice.

- tofore made, the in 'uidualparticles of the;

are converted sound jwaves' by the tele-- phone receiver. "When'the electric impulses Heretofore it has been customary to have granular material ill'thfl transmitter in a free loose state, the result being that with of the 'pe in question, as heregranular' material move relatively to each to i a considerable; extent, and obj actionable noises :areeonsequently produced when the 7 produced on said by such transmitters an mp r m pe w phonograph Q iborder {to fond-"1a phonograph record, the thus formedisfillediwith defects which produce foreign and unpleasant surand make the commerelally un-- face noises when' the record is reproduced mtisfaetory. one: thefobiects'ofmy in ventionyiszto overcome thesedefects; and I is preferably-madmmovable or adjustable clearl understoody; attention is hereb di rec to the accompanying ing .a,partoi :spec1fication and embodiment of- -my inv ti the l1ne'2'-2 of Fig. 1. .j

design other suita 1e material, is'mounted. The, riphery ofj'the diaphragm is" secured w tween gaskets} and fiyformedof rubberio soby.providing means wherebythe grauiykejt'sfbeingsecurely held between the sound;

. conductive-material is sc-packed in bei-jtweefit eyepiem yer the'individual si-'- "tiel eflie I bcx" body and a metallicring'fi threaded inw theiinterioroi the flange 2.} 2A hollow neck '7;

' Patented May 22,1917. i

relatively to the other so that thedesired nitial pressure between the electrodes and the granular material may bereadily obtamed, another object of my inventionibeing to.prov1de.means, such as a compression spring 'coacting with the adjustable electrode, to automatically maintain said preeatthe desired'amount. Means are also provided whereby the pmure of the spring or its equivalent may be regulated at A furtherobje'ct of my iiivention is to provide means for resistin moyement or viration of the saidmova 1e or adjustable electrode by rapid vibrations, such as those produced upon Y the vby sound 10 waves, the electrode. in! uestion acting. dur ingthe vibration of t e diaphragm" Sllbf i stantially asif it were stationary but being", movable'by the spring or its equivalent to produce'the desired inifial'pressure; Other objects ofmy' invention will a pear more fully in th "following specification and ap: :p nded cla ginst. V

invention may be more In order that my drawmg o Which I, "i"- 1;

Figure'l isa central longitudinal sectional 7 view partly elevation.-of- -the preferred Fi 2 is a we section thereof takenen Referring tothedrawin gs, the hmherirri j ates a metallic sound boxl having an QO arched body portion from which extends an:

annular flgngg' 2 within whi h the dial phragm: 3 preierably formed-of mica' o other suitableyielding material, the "said ga 10 tnds cen i' y hfi and hasi s'ecured to the same'the tapering. mouth pie e. 8. Ely-m eiwh hi the 'smnd y'rav ii'om} the "person s'peflki g or other. source sound are caused to converge into thei'sonn material with a predetermined initial press tures of my improved device wherein my in- I ventlon'resldes, metalllc arms or brackets 9 I and 9 secured to the flange 2 at diametrically opposite posit-ions thereon serve as a support for abridgebar 10.-- The latter is secured-at each end to one-of the arms or brackets 9 or 9 The means for securing each end of the bridge barto the adjacent bracket comprise an insulating-bushing 11 extending through an opening in the bar'1 0 .and having a flange-like portion interposed between the 'said'barand the horizontal portion 12 of the bracket, and a screw 13 passing through. the bushing and also' through an insulating washer 14 interposed between the head ofthe' screw and the bridge bar, the screwbeing threaded into the part 12. By means-of the above described con central'opening' in the bridge bar 10 and is arranged in axial alinement with the center of the diaphragm and the sound box neck 7 -'A lock nut 16' is employed to hold the sleeve 16 in proper adjustment with respect'to the diaphragm. Slidable longitudinally within.

the sleeve or guide'16 is a carbon electrode 1 -7 andsecured to the'diaphragm 'op osite said electrode is -;a second" electr carbon of-'a diameter slightly-greater than that of the electrode 1 7, the electrode l8obe- 'ingmovable toward and away from the elec-.

trode 17- by the'vibrationvofthe diaphragm.

vThe face -Of'-'th6 electrode ,17 is arranged closely adjacent the-electrode- 18 and is ref ,erably of curved concave formfsoas to orm between the two electrodes,*.a-pocket or cell,

periphery by' an annu arqmember 20 of yielding-insulating material,- such as cotton fabric, which annular member is-secured to the periphery of the electrode 17 and bears 1 against the face ofthe electrode 18. f A thin-- layer 21 of granular or finely divided carbon; is'placed within the cell made as described above} The outer end offthesleeve- 16 is closed' by a cap 22 threaded on the periphery" of, said sleeve. A screw-'23 is threaded i-throu-gh the' -cen'terof said cap andis. projvide'd, at its inner-fiend with an annular groove '24 within which an end of-the coil spring 25 is rotatably secured; the opposite end of the'spring .enga ing within a .circu larfglr iove 27 formed in the head or projecf tion. 28. of the e1ectrode'17 .'YWith this'.con-- struction, the spring '25 'a'cts to constantly press the electrode 17 against the granular sure and the said material completely fills 1 and is packed within the cell formed by the electrodes and the part 20 so that the obj ectionable individual movements-of the carbon e; 18' formed preferably of'a thincir'cularsheet of tion with sa1 I conductor, 34 passing through small openfrom which arm 9". h r Many modifications-"may obviously be "the latter "being completel .inclosed aroundlf e h sp Structure herein, 1

' scribed without departlng from the spirit particles hereinbefore referred toiare effec- .tively prevented." The set screw 23 may ob-v viously be' adjusted at will to obtain the de sired initial degree of pressure of the spring 25. A lock nut '23 serves to lock the set screw 23in adjusted position. The cap 22 has an airtight connection with the sleeve 16 and the electrode 17 fits closely within the latter sothat these parts together constitute a dash-pot which, while permitting slow movement of the electrode 17 whereby the latter may adjust itself to place the desired 9 inltial pressure on the finely divided carbon,

acts pneumatically to prevent rapid vibra'-- tion. of said electrode such aswould beproduced by the vibration of the diaphragm.- v The inner end of the adjustable sleeve 16 co- 1 acts with ashoulder formed on the inner end portion of the electrode 17 to so limit the movement of the latter away fIOIIL'tllB electrode 18 as to prevent the escape of the granular material 21 from'between the electrodes. A lead wire 29 is secured between bridge member 10 and a washer 30 by means of a screw 31, this lead wire thereby having an electrical connection with the electrode 17 through the electrically bridge bar and sleeve 16. Electrical connection is made with theelectrode 18 by means of a wire 32 ,whichis secured'in electrical conductive 1 connection with arm 9 by screw 33, the electrode 18 bein placed in electrical connec arm by means-of a wire or ings. 35 and' 35 in the diaphragm and suita'bly'secured atone end to the said electrode andat the other end to-the sound box body the current is conveyed to ofmy invention and'I wish, therefore, not to be limited to the exact detailsherein disclosed.

' "What'I claim as new the deem-5 m;

tect by Letters Patent is as follows:

1.111 a"micr oph0ne -transmitter, the combination of an :electrode arranged.- toyibrate 'in accordance with pulsations transmitted thereto, a second electrode movable relatively-to-said'first. named electrode, granu-' 'lar conductivei'material between said. elec- 1 i trodes, gm'eans pjremmg said: second electrode toward said' fi'rstnan'led electrode to OOH]:

Press. said material between said electrodes, I and pneumatic mea'nstending to prevent:

.- vibration ofsaidsecond electrode upon the vibration of said first named electrode,

stantially 'as described.

2. In a microphone transmitter, the com-:-

electrode movable toward andraway from' said first named electrode; granular conducof said second electrode by the vibration of said first named electrode, substantially as desc bed.

4. In a microphone transmitter, the combination of an electrode arranged to vibrate in accordance with pulsations transmitted thereto, a second electrode movable rela tively -to said first named electrode, and 'means coacting with said second electrode to formia pneumatic dash pot for preventing vibration of said second electrode by the,

vibration of said first named electrode, substantially as described. 36

bination of an electrode arranged to vibrate in accordance with pulsations transmitted thereto, a second electrode -movable relatively to said first named electrode, one of said electrodes having a pocket or cell extending close to theother' electrode, granular conductive material filling said pocket or cell, means coacting with said electrodes to prevent individual movement of the parelectrode by the vibration of the first electrode, substantially as described. g

6. Ina microphone transmitter, thecombination of an electrode arranged to vibrate in accordance with pulsations transmitted thereto, a second electrode movable ridetively to said first named electrode,' yielding insulating means coacting with said electrodes from an 'lin'closed cell,.granular conductive material. said cell, means pressing said second electrode toward said .first named electrode to pack said material in said cell; pneumatic means tending to prevent vibration of said second electrode by the vibration of said first electrode, substantially as described,

" ,7. In a microphone transmitter,

, the combi-" .withulsations transmitted "thereto, a second e ectrode movable relatively to"said. first named electrode, and Iyielding means coacting with said electrodesto form an inclosed cell,'granular tive material between said electrodes, and pneumatic means for preventing vibrations 5. In a microphone transmitter, the coniticles of said material upon the vibration of said first electrode, and pneumatic meanstending to prevent vibration of said second trode toward said nation offan electrode arranged to vibrate in l conductive material within said cell, means pigtssing said second electrode toward said named electrode to pack said material in said cell, means for regulating the pressure of said pressing means, and pneumatic means to prevent vibration of said second electrode by the vibration of said electrode, substantially as described.

- "8. In a microphone transmitter, the com -'bination of an electrode arranged to vibrate 7 5 in accordance with pulsations transmitted thereto, a second electrode movable relatively to said first named electrode, yielding insulatingmeans coacting with said electrodes to form an inclosed cell, granular conductive so material within said cell, means pressing said second electrode toward said first named electrode to pack said material-in said cell, and means coacting with said second electrode to form a pneumatic dash pot tending 5 Y to prevent vibration of said second electrode by the vibration of saidfirst electrode, substantially as described. 9. In a-device of the class described, an electrode arranged to vibrate in accordance with pulsations transmitted thereto, a second electrode movable relatively to said first named electrode, yielding insulating means coacting with said electrodes to form an inclosed cell, granular conductive material fill 5 1 ing said cell, means pressing said second elec-. trode toward said first named electrode, and pneumatic means tending to-prevent vibra .tion of said second-electrode, substantially asdescribed. 1

10. In a device of the class described, an electrode arranged to vibrate inaccordance i with pulsations transmitted thereto, a sec- Y ond electrode movable relatively to said first named electrode, yielding insulating means coactingwith said electrodesto form an in-' 5 h closed cell, granular conductive material filling said cell; means ressing said second elec- I fii'st namedelectrode, and V means coacting with said second electrode to form a pneumatic dash-pot tending to.pre- 5 vent vibration of said second electrode, substantially as described. i g 11. In a device of: the classdescribed, the

combination. of a sound box, an electrode supported thereby, a bridge onsaid'sound-f box, a guide supported by said brid asceond electrode movablem said gmde s'aid' guide being adjustable and. coacting with said second electrode to limit the movement 1201'v thereofin one direction, granular'condu'ctive; material betweensaid electrodes; andmeans.

tending automatically to 'movesaid second;

electrode toward theother stantially as described. 1 H V 12. In a-de'vice ofthe class described,;the combinationgof ga vibratoryelectrode com prising 8. dia hragrn; a sound boasupport; ing said-,diap gm with'one side of-the diar' phragm open '-to the atmosphere, a second 130 electrode, sub- P electrode movable relatively to said first named electrode, means pressing said second electrode toward said first named electrode, and pneumatic means arranged on the side of the diaphragm open to the atmosphere tending to prevent vibration of said second electrode, substantially as described.

13. In a microphone transmitter, the combination of an electrode arranged to vibrate in accordance with pulsations transmitted thereto, a second electrode movable relatively to said first named electrode, and pneumatic means for preventing vibrations of said second electrode, substantially as described.

14. In a device of the class described, an electrode arranged to vibrate in accordance with pulsations transmitted thereto, a second electrode movable toward and away from said first named electrode, granular conductive material between said electrodes, and a support for said second electrode, said sup port coacting with said secondelectrode to limit the movement of the latter away from the first electrode to thereby prevent the escape of said granular material from between second electrode to form a dash-pot tending to prevent vibration of said second electrode, and means Within said dash-pot pressing said second electrode toward saidfirst electrode, substantially as described.

This specification signed and witnessed this 8th day of May, 1913. v

NEWMAN H. HOLLAND. Witnesses:

FREDERICK BACHMANN, MARY J. LAIDLAW.

It is hereby certifiedtthat in Letters Patent No. 1,226,886, granted May 22, 1917.

upon thernpplication of Newman H. Holland, of West Orange, New Jersey, for an improvement in Telephone-Transmitters, an error appears in the printed epecification requiring correctioxi as foil owe: Page 3, line 51', clhim 6, for the word from read toform, and that the said Letters Patent ehou1d-be read with this correction therein that the name may conform to the record of the case in the Petent0flioe.

Signed and sealed this 20th day 0! November, A. D., 1917.

[SEAL] R. F .W'HITEHEAD,

Acting Commissioner of Patents. 

